Method of making heat-resistant chocolate and chocolate-like compositions with reduced apparent viscosity

ABSTRACT

A heat-resistant chocolate or chocolate-like composition is prepared by mixing a polyol, such as sorbitol or glycerine, with a flowable chocolate or chocolate-like composition through an increased apparent viscosity phase. Upon continued mixing, the mixture returns to a reduced apparent viscosity (fluid) phase. The mixture is subsequently handled in the same manner as an unmodified composition. Upon aging and stabilization, the modified chocolate or chocolate-like composition demonstrates a reduced tendency to deform at elevated temperature, is less prone to stick to packaging or fingers, and maintains the desired flavor, texture, mouth feel, and other characteristics of ordinary chocolate. The heat-resistant chocolate or chocolate-like composition of the invention is suitable for use in the same manner and for the same purposes for which ordinary chocolate and chocolate-like compositions are used, with the additional benefit of heat-resistance.

CROSS-REFERENCE TO RELATED APPLICATION

This application is the National Stage of International Application No.PCT/US99/13543 and claims the benefit of U.S. Provisional PatentApplication Serial No. 60/089,437, filed Jun. 16, 1998.

BACKGROUND ART

The present invention is directed toward a method of forming aheat-resistant chocolate or chocolate-like composition and moreparticularly, toward modified products that demonstrate reduced apparentviscosity in the molten phase. As a result of this reduced apparentviscosity, these products may be handled in the same manner asunmodified compositions. Such products have a reduced tendency to meltor to deform at elevated temperatures and have a tendency to stick tofingers or packing materials.

Chocolate products are typically mixtures of liquid cocoa, cocoa butter,sugar, lecithin, and possibly milk and flavoring substances.Chocolate-like products contain substantially the same ingredients as achocolate composition and also use any number of vegetable fats, cocoabutter replacers and/or extenders. Since the resulting fat content ofthese products is relatively high, the corresponding melting point is afunction of the melting point of the fat contained therein.

Ordinary chocolate and chocolate-like products characteristically tendto melt at temperatures as low as 30° C. As a result, chocolate candies,and chocolate-like coatings for biscuits, cookies, and confectionsquickly lose their original appearance, and are no longer suitable forconsumption when they have been exposed to high temperatures.

Many processes have been proposed to avoid some of the disadvantagesnormally associated with ordinary chocolate products. The productsobtained by these various methods, which may have more heat-resistancethan their ordinary counterparts, often have an unpleasant taste ortexture (“mouth feel”), are expensive to produce commercially, requirethe production of separate ingredients, cannot be produced withinestablished manufacturing processes, or are beyond the current legaldefinition for chocolate.

U.S. Pat. No. 2,166,806 discloses a product and method for preventingthe separation of oils, specifically in peanut products, so that suchpeanut products, for example, peanut butter, will have a reducedtendency to segregate. This patent describes the addition of glycerine,a polyol, to the peanut product, in an amount upward of one-tenth of onepercent, and as high as twenty percent. However, the products andprocesses disclosed in this patent apply only to peanut products. Thepotential uses with chocolate and chocolate-like compositions are notaddressed. It must be noted that the fat in peanuts is substantiallyliquid at ordinary temperature (20° C.) and, therefore, has no bearingon or any reference to melting. A disadvantage to this process is thatthe peanut product to be modified thickens rapidly and allows littletime for further use of the product. Also, additional equipment isneeded to incorporate the glycerine at the latest possible time beforefurther processing to prevent premature setting. Furthermore, theelevation of viscosity and yield value of the modified peanut productand its impact on the product's commercial production are not addressed.

European Patent No. 459,777 discloses a structured fat emulsion forincorporation into a confectionery coating as the fat ingredient. Adisadvantage involved with this process for producing a confectionerycoating containing a structured fat emulsion is that the emulsionsdescribed are inherently unstable and are therefore difficult andexpensive to produce and store. Furthermore, the machinery required toproduce the emulsion is alien to chocolate manufacture, thus significantadditional capital investment would be required. Another disadvantage isthat the preferred fat is partially hydrogenated fat. Such fats arethought to engender physiological properties that are currently thoughtto be undesirable, and are, therefore, less commercially desirable.Additionally, the use of such fats is not allowed as they are beyond thecurrent legal definition for chocolate.

U.S. Pat. Nos. 5,149,560; 4,446,166; 4,081,559; 4,045,583; and 2,904,438and Swiss Patent Nos. 410,607 and 409,603 demonstrate the use of wateror moisture in chocolate compositions. Products produced by the methodsdescribed in these patents are prone to suffer an effect known as “sugarbloom” and initiate a progressively increased coarse mouth feel as thewater evaporates and the sugar crystallizes. Other disadvantages mayinclude: a lack of heat-resistance below the immediate surface of thechocolate, the need for expensive thermal treatments, controlledhumidity and difficult and costly storage conditions, and deficientquality of the finished products.

Swiss Patent Nos. 399,891 and 489,211 describe methods of incorporatingamorphous sugars into a chocolate composition during manufacture. Thesugars form a lattice structure that prevents collapse of the mass whenthe temperature exceeds the melting point of the chocolate fat. Such astructure is delicate, unstable, and difficult to incorporate in acommercial setting.

U.S. Pat. No. 4,446,166 describes a chocolate composition containing awater-in-fat emulsion which provides a product containing at least 20%of the fat in solid form. The water-in-fat mixture, however, does notremain in liquid form during processing. Also, the presence of suchsolid materials may result in an undesired rough texture or mouth feel.

Other methods of moisture inclusion or fat immobilization have beenattempted. A disadvantage described in subsequent literature has beenthe elevation of chocolate viscosity and yield value that occurs as aresult of the employment of these methods.

It is known that Newtonian liquids (e.g., water) flow as soon as forceis applied. Viscosity remains constant regardless of the rate of shear.Viscosity refers to the measure of the internal friction of a fluid thatprovides resistance to shear (motion) when a fluid is stirred or poured.The greater the forces of internal friction (i.e. the greater theviscosity), the less easily the fluid will flow.

Non-Newtonian liquids are liquids whose viscosities vary according tothe rate at which they are stirred (also known as “shear rate”). Theyinclude plastic, dilatant, and pseudoplastic liquids, characterized bythe way a fluid's viscosity changes in response to variations in shearrate.

1. Plastic. This type of fluid will behave as a solid under staticconditions. Prior to the inducement of any flow, a minimum force isrequired to start the liquid moving.

2. Dilatant. The viscosity increases with an increasing shear rate.

3. Pseudoplastic. The viscosity decreases with an increasing shear rate.

Yield value is the minimum force required to start a non-Newtonianliquid moving. When the yield value upon a non-Newtonian liquid isachieved and exceeded, fluidity results. The higher the yield value, themore resistant the material is to flow. “Plastic Viscosity” is ameasurement relating to the amount of energy required to keep certainnon-Newtonian liquids moving once they have started to move.

Molten chocolate is a non-Newtonian fluid, but is typically referred toas a pseudoplastic fluid, demonstrating unique rheologicalcharacteristics. Viscosity measurements of chocolate in the molten statemay be referred to as “apparent viscosity”, as variations of shear ratewill affect the measured viscosity. Typically, apparent viscosity is afunction of applied shear rate and shear stress without regard to yieldvalue. See, Nelson and Beckett, Industrial Chocolate Manufacture andUse, 1988; Instruments and Control Systems. vol. 32, No. 6, June 1959;and “More Solutions to Sticky Problems”, Brookfiled EngineeringLaboratories, Inc., 1985.

U.S. Pat. No. 4,464,927 discloses a method for increasing the viscosityof a chocolate composition so that the composition will be non-flowableat temperatures well above the normal melting point of the cocoa butter(or in the case of imitation chocolates, the melting point of vegetablefats and the like). This patent describes adding a liquid polyol, forexample, glycerine, sorbitol, or mannitol of 0.2 to 5.0 wt % to achocolate composition after tempering. A perceived disadvantage of thisprocess is that the chocolate product to be modified sets rapidly, i.e.,between 15 to 60 seconds, and allows little time for further processingof the chocolate, for example, molding or enrobing. Another disadvantageof this method is that special additional equipment may be needed toincorporate the polyol at the latest possible time before furtherprocessing of the chocolate to prevent premature setting of thechocolate.

U.S. Pat. No. 5,523,110 discloses a heat-resistant chocolate whichcomprises mixing of a polyol gel in particulate form with a flowablechocolate or a flowable mixture of ingredients for preparing chocolateand chocolate-like compositions. The polyol gel is formed by the use ofgelling agents such as pectin, xanthan gum, locust bean gum,kappa-carrageenan agar, sodium alginate, gelatin, and iota-carrageenan.Other gelling agents, such as polysaccharides, for example, glucomannan,are suggested for use to form a firm gel around a polyol. A disadvantageof this method is that such gelling agents are not permitted inchocolate by regulation in many countries, and therefore suchcompositions may not labeled as “chocolate.”

U.S. Pat. No. 5,523,110 also provides a gelation method by which a drypolyol mixture containing up to 95% by weight of water is used. Adisadvantage of this method and process is that the product produced mayhave an undesirable taste and/or texture (“mouth feel”) due to thepresence of a high amount of water in the chocolate. In addition, thepatent further provides a method for forming and dispersing aparticulate polyol gel by “. . . freezing the polyol gel from about −170C. to −200 C. and then grinding it in a cold grinder . . . ” Adisadvantage of this method and process is the cost prohibitive use ofrefrigerants such as liquid nitrogen needed to achieve low temperatures.Such a technique is alien to commercial chocolate production.

U.S. Pat. No. 5,445,843 discloses a process for improving the heatresistance of chocolate or chocolate-type products with a reducedtendency to deform at elevated temperatures including the step of mixinga polyol encapsulated within an edible lipid, for example, fat or oil,and added in particulate form to a flowable chocolate composition. Theresultant chocolate product is described as having a slower “settingtime” when compared to other methods. A disadvantage of this process isthat in a commercial setting, it may be difficult to maintain therequired “gentle mixing” of the composition. That is, pumps, mixers, andother operations in a commercial chocolate production setting may applymore mechanical energy than allowed by this patent.

Furthermore, commercial chocolate is best stored at about 40° C. See, R.B. Nelson and S. Beckett, Industrial Chocolate Manufacture and Use(1988). In addition, commercial chocolate is typically melted to 60° C.;lowered to between 46 and 49° C.; and pumped at a temperature between43.5 and 49° C. prior to tempering. See, D. Hawk, et al., NationalConfectioner's Association—All Candy Expo educational session “ChocolateHandling, Problems and Solutions,” (Jun. 12, 1997). Handling of modifiedchocolate beyond the parameters set by U.S. Pat. No. 5,445,843 may causepremature setting of the modified chocolate and, in a commercialsetting, may result in disastrous consequences. Other disadvantages ofthis process are that the encapsulated particulate must be produced as aseparate ingredient, and the particulate must be stored so as to remainin a solid form during the mixing and processing of the chocolatecomposition to prevent a premature setting.

U.S. Pat. No. 5,445,843 provides the following example:

“5 parts of the encapsulated glycerol as prepared . . . are mixed with100 parts of a flowable mixture of conched chocolate at 30 degrees C.for 15 minutes. The chocolate remains flowable for several minuteswithout setting . . . ”

It is well known to those skilled in the art that molten chocolate in acommercial setting must remain flowable for many hours.

It has been described and demonstrated in the prior art discussed abovethat the increase in viscosity of a chocolate composition by polyol orwater inclusion would render certain methods impractical or unusable ina commercial setting. The prior art teaches that chocolate and imitationchocolate compositions which exhibit high viscosity in their fluidphases are to be avoided. It is also self-evident to those skilled inthe art that a method to produce heat-resistant chocolate compositionsconsidered typical to chocolate manufacturing would be preferred overthe use of special processing equipment. Furthermore, special handlingof ingredients and/or finished products, for example, high humidity orlow temperature storage is not a preferred approach.

DISCLOSURE OF THE INVENTION

The present invention is designed to overcome the deficiencies of theprior art discussed above. It is an object of the present invention toprovide a modified chocolate or chocolate-like composition with reducedapparent viscosity in the molten state, which has the taste, texture,and mouth feel of traditional chocolate or chocolate-like compositions.

It is a further object of this invention to provide a method formanufacturing a heat-resistant chocolate or chocolate-like compositionthat is little or no more complicated than the traditional method ofmanufacturing chocolate.

The present invention involves a method of adding a polyol to a flowablechocolate or chocolate-like composition. The elevation of viscositynormally associated with the introduction of the polyol is overcome bycontinued mixing of the composition through a stage of high apparentviscosity until the composition returns to a reduced apparent viscosityand flowable state.

These and other objects, features and advantages of the presentinvention will be clearly understood through a consideration of thefollowing detailed description.

BEST MODE FOR CARRYING OUT THE INVENTION

In accordance with the present invention, 0.5 to 20-wt. % of a liquidpolyol, for example, glycerine, is added to a flowable chocolate orchocolate-like mixture before or after the mixture is tempered. Theliquid polyol is mixed with the chocolate or chocolate-like compositionat normal processing temperatures, for example approximately 100° F. Thecomposition is mixed through a phase of increased yield value andapparent viscosity, exhibiting reduced-flow characteristics, e.g., a“plastic phase,” for a time, until the composition has returned to aflowable composition. The viscosity of the modified composition exhibitsincreased yield value. However, the apparent viscosity is substantiallythe same as or lower than the unmodified composition. The modifiedcomposition is handled in substantially the same manner as an unmodifiedcomposition, and may remain flowable for between several hours andseveral days.

After such a modified composition is produced and held for a time, thecomposition will demonstrate improved heat-resistance. (The term“reduced apparent viscosity” refers to the viscosity of the compositionwhen it has been modified yet is still in its molten state as comparedto an unmodified composition.) Upon returning to the flowable state, themodified chocolate or chocolate-like composition may be tempered,deposited, molded, or used as a coating, and when allowed to age andstabilize, develops heat resistance. The modified chocolate compositionhas an extended “working time” of a length sufficient for subsequenthandling in the same manner as traditional chocolate. In addition, themodified chocolate composition may be produced without the costlymethods and ingredients described in the prior art.

In carrying out the process of the present invention, the chocolatecomposition which is to be modified may be a milk chocolate, asemi-sweet chocolate, a white chocolate, or any composition known as a“compound,” “confectionery,” or “pastel” coating. The coating maycontain any edible fat or oil. Ordinarily, the fats used are animal orvegetable in origin and are edible. However, synthetic materials havingsubstantially similar chemical compositions to fats and oils may also beused. The preferred fats and oils are lower melting point fats thatexhibit some tendency to flow at ambient or slightly elevatedtemperatures. This includes cocoa butter, other butter products, peanutoil, and vegetable oils. However, substantially any fat or oil can beconverted into a product and rendered useable, i.e., mixed through to aflowable state by using the method of the present invention.

In a preferred embodiment, the invention is particularly applicable toproducts containing low melting point fats or oils, for example,chocolate or imitation chocolate products. Polyols that may be used arestraight or branched-chained hydrocarbon compounds containing at leasttwo hydroxyl groups on the carbon skeleton. Compounds which includeother functional groups, for example, double bonds or carboxyl groups,may also be used, provided that at least two hydroxyl groups arepresent. There is no upper limit to the number of carbon atoms orhydroxyl groups that may be present on the structure.

Polyols are not generally soluble in fats or oils, and as a result,those that occur naturally as liquid are preferred. Glycerine, forexample, is preferred as a matter of convenience, although other polyolmaterials that readily form solutions having a substantial concentrationof the polyol are acceptable, for example, sorbitol. Other materialsthat can be utilized in the invention include mannitol and corn syrup,for example, 42 D.E., 55 D.E.

Continued mixing may be carried out during chocolate making or afterchocolate making. If mixing occurs after chocolate making, it may bebefore tempering, after tempering, or during tempering of the chocolate.Continued mixing may be low shear, such as in a planetary mixer, or highshear, such as in a scraped surface heat exchanger. Continued mixing maybe carried out at low speed or high speed.

In the production of modified chocolate and chocolate-like compositions,any conventional chocolate or chocolate-like formulation may beemployed. Such formulations normally include chocolate liquor, milksolids, sugar, cocoa butter, cocoa butter replacers, lecithin, andflavors. Other ingredients, all of which are known by those skilled inthe art, may also be used. Typically, the ingredients used to make achocolate or chocolate-like composition are mixed, refined, conched, andstandardized as to viscosity, tempered, and utilized to form a finishedproduct or to enrobe or coat a pre-formed center. The finished productis then typically cooled or refrigerated after it is put into its finalform.

The invention will further be understood through the followingillustrative, non-restrictive examples.

EXAMPLE 1

A 600-gram sample of a commercially available milk chocolate (CashmereBrand Milk Chocolate, Wilbur Chocolate, Litiz, Pa.) was placed into afive quart Hobart mixer, and was melted at approximately 47° C. Fivepercent of glycerine was added and mixing continued. Withinapproximately 45 seconds, the sample became highly viscous. Mixingcontinued, and within 20 minutes, the sample had once again becomeflowable. The sample was then tempered and molded in the traditionalmanner. Within 24 hours, the sample became heat-resistant.

EXAMPLE 2

A 600-gram sample of the same flowable chocolate from Example 1 wasplaced into a five quart Hobart mixer where it was melted atapproximately 47° C. Five percent of glycerine was added, and the samplewas returned to mixing. Once the sample had been returned to a fluidstate, the mixer was then set to a low mixing speed and left on forapproximately thirty (30) hours. The sample was then tempered, molded,and cooled in the traditional manner. The sample became heat resistantafter three days.

EXAMPLE 3

A 20 kilogram sample of a commercially available milk chocolate (SableBrand Milk Chocolate, Wilbur Chocolate, Litiz, Pa.) was placed into an80 quart Hobart mixer and was melted at approximately 47° C. Thechocolate was then cooled to approximately 38° C. Three percent ofgylcerine was added and the sample was mixed. After 15 minutes thesample became fluid. The sample was tempered, molded, and cooled in thetraditional manner. The sample became heat resistant after two days.

EXAMPLE 4

A 230 kilogram sample of the same chocolate used in Example 3 was placedin a swept-surface paddle mixer and was melted at approximately 47° C.The chocolate was then cooled to approximately 38° C. Three percent ofglycerine was added. The sample was then mixed. Within 30 minutes thesample became fluid and was pumped, tempered, molded, and cooled in thetraditional manner. The sample became heat resistant after three days.

EXAMPLE 5

A semi-sweet chocolate was prepared to the following formula:

Ingredient Parts By Weight Refined sugar 50 Chocolate liquor 40 Cocoabutter 9.7 Lecithin 0.3 Total 100

The above material was mixed in a 12 quart Hobart mixer for 6 hours at50° C. The sample was cooled to 40° C. Eight parts of a polyol was addedto the composition, and the sample was mixed until the sample was againflowable. The sample was then tempered, molded, and cooled in thetraditional manner. The sample became heat resistant overnight.

EXAMPLE 6

A 600-gram sample of a commercially available confectionery or “fudge”coating (Blommer Chocolate Company, Chicago, Ill.) was placed into afive quart Hobart mixer and was melted at approximately 47° C. Eightpercent of a polyol was added and mixing continued. Within 45 minutesthe sample became flowable. The sample was then used to enrobe grahamcrackers. Within 48 hours, the coated graham crackers becameheat-resistant.

It will be readily apparent to those skilled in the art that a widevariety of food, cosmetic, pharmaceutical, and other compositions can beformulated utilizing the method of the invention to produce a widevariety of novel products. The present invention may be embodied inother specific forms without departing from the spirit or essentialattributes thereof and accordingly, reference should be made to theappended claims rather than to the foregoing specification as indicatingthe scope of the invention.

What is claimed is:
 1. A method for producing a heat-resistantchocolate-like composition with reduced apparent viscosity comprisingthe steps of: providing a flowable chocolate-like composition; adding0.5 to 20-wt % of a liquid polyol to said composition to form a mixturehaving an increased apparent viscosity; and continuously mixing saidmixture until said mixture has a reduced apparent viscosity.
 2. Themethod for producing a heat-resistant chocolate-like composition withreduced apparent viscosity as claimed in claim 1 wherein said polyol isglycerine.
 3. The method for producing a heat-resistant chocolate-likecomposition with reduced apparent viscosity as claimed in claim 1further including the step of tempering said composition before saidadding step.
 4. The method for producing a heat-resistant chocolate-likecomposition with reduced apparent viscosity as claimed in claim 1further including the step of tempering said mixture after said addingstep.
 5. The method for producing a heat-resistant chocolate-likecomposition with reduced apparent viscosity as claimed in claim 1further including the step of tempering said composition during saidadding step.
 6. The method for producing a heat-resistant chocolate-likecomposition with reduced apparent viscosity as claimed in claim 1wherein said chocolate-like composition is chocolate.